<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var number = 1;

    var obj = {
        number:2,//=>3
        showNumber:function(){
            //this=>obj
            this.number = 3;

            //自执行函数
            (function(){//window
                console.log(this.number);  //=>1
            })();

            console.log(this.number);
        }

    };
    obj.showNumber();



    //4.   1    3





    //5.   1    2





    //2.   3    2
    //3.   2    3
    //6.   .....

</script>
</body>
</html>